Electronic smoking device, cartomizer and liquid reservoir

ABSTRACT

There is provided a liquid reservoir for an electronic smoking device. The liquid reservoir (34) has a body (110) forming a hollow tube surrounding a central passage (32) connecting an air inhalation port (36) with a further port for attaching the liquid reservoir (34) to a further portion of the electronic cigarette (10). The liquid reservoir (34) further has a nozzle (132) towards the central passage (32), the nozzle (32) being configured to release liquid from the reservoir (34) only when pressure drop along the nozzle (32) exceeds a threshold pressure. A user can produce the pressure drop by sucking at the air inhalation port (36) and/or by manually changing a length of the central passage (32) thereby causing compression of the liquid reservoir (34).

FIELD OF INVENTION

The present invention relates generally to electronic smoking devicesand in particular electronic cigarettes as well as cartomizers andliquid reservoirs for electronic smoking devices.

BACKGROUND OF THE INVENTION

An electronic smoking device, such as an electronic cigarette(e-cigarette), typically has a housing accommodating an electric powersource (e.g. a single use or rechargeable battery, electrical plug, orother power source), and an electrically operable atomizer. The atomizervaporizes or atomizes liquid supplied from a reservoir and providesvaporized or atomized liquid as an aerosol. Control electronics controlthe activation of the atomizer. In some electronic cigarettes, anairflow sensor is provided within the electronic smoking device whichdetects a user puffing on the device (e.g., by sensing an under-pressureor an air flow pattern through the device). The airflow sensor indicatesor signals the puff to the control electronics to power up the deviceand generate vapor. In other e-cigarettes, a switch is used to power upthe e-cigarette to generate a puff of vapor.

Some electronic smoking devices comprise a cartomizer which is areplaceable unit comprising the atomizer and the reservoir for theliquid.

SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention there is provideda liquid reservoir for an electronic smoking device. The liquidreservoir comprises a body forming a hollow tube surrounding a centralpassage connecting ports for attaching the liquid reservoir to furtherportions of the electronic cigarette. The liquid reservoir furthercomprises a nozzle towards the central passage, the nozzle beingconfigured to release liquid from the liquid reservoir only whenpressure drop along the nozzle exceeds a threshold pressure. A user canproduce the pressure drop by sucking at an inhalation port of theelectronic smoking device and/or by manually changing a length of thecentral passage thereby causing compression of the liquid reservoir.

The characteristics, features and advantages of this invention and themanner in which they are obtained as described above, will become moreapparent and be more clearly understood in connection with the followingdescription of exemplary embodiments, which are explained with referenceto the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, same element numbers indicate same elements in each ofthe views:

FIG. 1 is a schematic cross-sectional illustration of an exemplarye-cigarette;

FIG. 2 is an exemplary illustration of a liquid reservoir according toan aspect of the invention;

FIG. 3 is an exemplary illustration of the liquid reservoir of FIG. 2partly dissembled;

FIG. 4 is a schematic cross-sectional illustration of FIG. 2 when theliquid reservoir is uncompressed;

FIG. 5 is a schematic cross-sectional illustration of FIG. 2 when theliquid reservoir is compressed;

FIG. 6 is a schematic cross-sectional illustration of a further liquidreservoir according to an aspect of the invention;

FIG. 7 is a schematic cross-sectional illustration of a yet furtherliquid reservoir according to an aspect of the invention, and

FIG. 8 is a schematic cross-sectional illustration of an even yetfurther liquid reservoir according to an aspect of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Throughout the following, an electronic smoking device will beexemplarily described with reference to an e-cigarette. As is shown inFIG. 1, an e-cigarette 10 typically has a housing comprising acylindrical hollow tube having an end cap 16. The cylindrical hollowtube may be single piece or a multiple piece tube. In FIG. 1, thecylindrical hollow tube is shown as a two piece structure having abattery portion 12 and an atomizer/liquid reservoir portion 14. Togetherthe battery portion 12 and the atomizer/liquid reservoir portion 14 forma cylindrical tube which is approximately the same size and shape as aconventional cigarette, typically about 100 mm with a 7.5 mm diameter,although lengths may range from 70 to 150 or 180 mm, and diameters from5 to 20 mm.

The battery portion 12 and atomizer/liquid reservoir portion 14 aretypically made of steel or hardwearing plastic and act together with theend cap 16 to provide a housing to contain the components of thee-cigarette 10. The battery portion 12 and an atomizer/liquid reservoirportion 14 may be configured to fit together by a friction push fit, asnap fit, or a bayonet attachment, magnetic fit, or screw threads. Theend cap 16 is provided at the front end of the battery portion 12. Theend cap 16 may be made from translucent plastic or other translucentmaterial to allow an LED 20 positioned near the end cap to emit lightthrough the end cap. The end cap can be made of metal or other materialsthat do not allow light to pass.

An air inlet may be provided in the end cap, at the edge of the inletnext to the cylindrical hollow tube, anywhere along the length of thecylindrical hollow tube, or at the connection of the battery portion 12and the atomizer/liquid reservoir portion 14. FIG. 1 shows a pair of airinlets 38 provided at the intersection between the battery portion 12and the atomizer/liquid reservoir portion 14.

A battery 18, a light emitting diode (LED) 20, control electronics 22and optionally an airflow sensor 24 are provided within the cylindricalhollow tube battery portion 12. The battery 18 is electrically connectedto the control electronics 22, which are electrically connected to theLED 20 and the airflow sensor 24. In this example the LED 20 is at thefront end of the battery portion 12, adjacent to the end cap 16 and thecontrol electronics 22 and airflow sensor 24 are provided in the centralcavity at the other end of the battery 18 adjacent the atomizer/liquidreservoir portion 14.

The airflow sensor 24 acts as a puff detector, detecting a user puffingor sucking on the atomizer/liquid reservoir portion 14 of thee-cigarette 10. The airflow sensor 24 can be any suitable sensor fordetecting changes in airflow or air pressure such a microphone switchincluding a deformable membrane which is caused to move by variations inair pressure. Alternatively the sensor may be a Hall element or anelectro-mechanical sensor.

The control electronics 22 are also connected to an atomizer 26. In theexample shown, the atomizer 26 includes a heating coil 28 which iswrapped around a wick 30 extending across a central passage 32 of theatomizer/liquid reservoir portion 14. The coil 28 may be positionedanywhere in the atomizer 26 and may be transverse or parallel to theliquid reservoir 34. The wick 30 and heating coil 28 do not completelyblock the central passage 32. Rather an air gap is provided on eitherside of the heating coil 28 enabling air to flow past the heating coil28 and the wick 30. The atomizer may alternatively use other forms ofheating elements, such as ceramic heaters, or fiber or mesh materialheaters. Nonresistance heating elements such as sonic, piezo and jetspray may also be used in the atomizer in place of the heating coil.

The central passage 32 is surrounded by a cylindrical liquid reservoir34 with the ends of the wick 30 abutting or extending into the liquidreservoir 34. The wick 30 may be a porous material such as a bundle offiberglass fibers, with liquid in the liquid reservoir 34 drawn bycapillary action from the ends of the wick 30 towards the centralportion of the wick 30 encircled by the heating coil 28.

The liquid reservoir 34 may alternatively include wadding soaked inliquid which encircles the central passage 32 with the ends of the wick30 abutting the wadding. In other embodiments the liquid reservoir 34may comprise a toroidal cavity arranged to be filled with liquid andwith the ends of the wick 30 extending into the toroidal cavity.

An air inhalation port 36 is provided at the back end of theatomizer/liquid reservoir portion 14 remote from the end cap 16. Theinhalation port 36 may be formed from the cylindrical hollow tubeatomizer/liquid reservoir portion 14 or maybe formed in an end cap.

In use, a user sucks on the e-cigarette 10. This causes air to be drawninto the e-cigarette 10 via one or more air inlets, such as air inlets38 and to be drawn through the central passage 32 towards the airinhalation port 36. The change in air pressure which arises is detectedby the airflow sensor 24 which generates an electrical signal that ispassed to the control electronics 22. In response to the signal, thecontrol electronics 22 activate the heating coil 28 which causes liquidpresent in the wick 30 to be vaporized creating an aerosol (which maycomprise gaseous and liquid components) within the central passage 32.As the user continues to suck on the e-cigarette 10, this aerosol isdrawn through the central passage 32 and inhaled by the user. At thesame time the control electronics 22 also activate the LED 20 causingthe LED 20 to light up which is visible via the translucent end cap 16mimicking the appearance of a glowing ember at the end of a conventionalcigarette. As liquid present in the wick 30 is converted into an aerosolmore liquid is drawn into the wick 30 from the liquid reservoir 34 bycapillary action and thus is available to be converted into an aerosolthrough subsequent activation of the heating coil 28.

Some e-cigarette are intended to be disposable and the electric power inthe battery 18 is intended to be sufficient to vaporize the liquidcontained within the liquid reservoir 34 after which the e-cigarette 10is thrown away. In other embodiments the battery 18 is rechargeable andthe liquid reservoir 34 is refillable. In the cases where the liquidreservoir 34 is a toroidal cavity, this may be achieved by refilling theliquid reservoir 34 via a refill port. In other embodiments theatomizer/liquid reservoir portion 14 of the e-cigarette 10 is detachablefrom the battery portion 12 and a new atomizer/liquid reservoir portion14 can be fitted with a new liquid reservoir 34 thereby replenishing thesupply of liquid. In some cases, replacing the liquid reservoir 34 mayinvolve replacement of the heating coil 28 and the wick 30 along withthe replacement of the liquid reservoir 34. A replaceable unitcomprising the atomizer 26 and the liquid reservoir 34 is called acartomizer.

The new liquid reservoir 34 may be in the form of a cartridge having acentral passage 32 through which a user inhales aerosol. In otherembodiments, aerosol may flow around the exterior of the cartridge 32 toan air inhalation port 36.

Of course, in addition to the above description of the structure andfunction of a typical e-cigarette 10, variations also exist. Forexample, the LED 20 may be omitted. The airflow sensor 24 may be placedadjacent the end cap 16 rather than in the middle of the e-cigarette.The airflow sensor 24 may be replaced with a switch which enables a userto activate the e-cigarette manually rather than in response to thedetection of a change in air flow or air pressure.

Different types of atomizers may be used. Thus for example, the atomizermay have a heating coil in a cavity in the interior of a porous bodysoaked in liquid. In this design aerosol is generated by evaporating theliquid within the porous body either by activation of the coil heatingthe porous body or alternatively by the heated air passing over orthrough the porous body. Alternatively the atomizer may use apiezoelectric atomizer to create an aerosol either in combination or inthe absence of a heater.

FIG. 2 is a schematic illustration of a liquid reservoir according to anaspect of the invention and in FIG. 3 the liquid reservoir of FIG. 2 isillustrated schematically in a partly dissembled state. FIG. 4 is aschematic cross-sectional illustration of FIG. 2 when the liquidreservoir is uncompressed and FIG. 5 is a schematic cross-sectionalillustration of FIG. 2 when the liquid reservoir is compressed.

The liquid reservoir 34 comprises a body in form of a hollow cylinder110 into which a tubal element 120 is inserted. The tubal element 120has an annularly protruding ring 121 on one end. The ring's 121 outerdiameter corresponds to the hollow cylinder's 110 inner diameter suchthat the hollow cylinder 110 can be closed at one end by insertion ofthe tubal element 120 into the hollow cylinder 110 with a toroidalcavity remaining between the tubal element 120 and the cylinder 110.

Through the ring 121 there is a pin hole 123. Cylinder 110, ring 121 andpin hole 123 are configured such that once assembled the cavity is waterproof as long as pressure drop along the pin hole 123 does not exceed athreshold pressure. I.e. to get liquid to escape from the cavity,through the pin hole 123, pressure has to be build up in the cavity.

For enabling a user to manually do so, the cartomizer depicted in FIGS.2 and 3 further comprises a hollow piston 130. The piston 130 is afurther tubal element with an outer diameter corresponding to the innerdiameter of the hollow cylinder 110 and, in addition, an inner diameterof the hollow piston 130 corresponds to an outer diameter of the tubalelement 120 such that the hollow cylinder 110 can be closed at the otherend by insertion of the piston 130 into the hollow cylinder 110 and ontothe tubal element 120. At an end of the piston 130 determined forinsertion into the cylinder there are an inner gasket ring 132 at theinner surface of the tubal piston 130 and an outer gasket ring 131 atthe outer surface of the piston 130. The inner gasket ring 132 seals thepiston 130 with respect to the tubal element 120. The outer gasket ring131 seals the piston 130 with respect to the hollow cylinder 110.Alternatively, the inner gasket ring 132 is provided around the tubalelement 120 and/or the outer gasket ring 131 is provided inside thehollow cylinder 110. The gasket rings 131, 132 may be positioned in anannular furrow.

The user then can move the piston inside the hollow cylinder therebychanging a volume of the cavity and thus the pressure in the cavity.

A limiting element 140 is further comprised. The limiting element 140 isformed to be hollow and cylindrical and comprises a plate 142 at oneend. An axial hole 119 is provided through the plate 142, the axial hole119 having a diameter corresponding to an outer diameter of the piston120. The limiting element 140 has an inner diameter corresponding to theouter diameter of the hollow cylinder 110 such that the limiting element140 can be fit on the hollow cylinder 110. In the embodiment depictedthe limiting element 140 comprises a female thread and the hollowcylinder 110 comprises a male thread such that the limiting element 140and the hollow cylinder 110 can be screwed together.

In a middle section, the piston 130 comprises a thickened part 134, alsocalled annular protrusion throughout this specification, which has anouter diameter larger than the axial hole 119. Hence the thickened part134 cannot pass through the axial hole 119. The limiting element therebylimits movement of the piston 130.

Between the thickened part 134 of the piston 130 and the other end ofthe hollow cylinder 110 there is arranged a resilient element which inthe example illustrated is a spring 150. The piston passes through thespring. The user, when pushing the piston for reducing the volume of thecavity, compresses the spring which, once the user stops holding thepiston, moves the piston back. The limiting element prevents the pistonfrom escaping from the hollow cylinder. Moving the piston into thehollow cylinder increases the pressure therein with liquid squirtingthrough the pin hole once the pressure increase exceeds a thresholdpressure. When the spring moves back the piston air enters into thecavity through the pin hole 123.

In one embodiment, a heating coil (atomizer) is an integral part of abattery portion of the electronic smoking device and the liquidreservoir is detachable from the battery portion. In one otherembodiment the atomizer is an integral part of the cartomizer and thecartomizer is detachable from the battery portion. In yet anotherembodiment the atomizer is detachable from both the liquid reservoir andthe battery portion. In the other embodiments, the atomizer,respectively the cartomizer, and the battery portion comprise elementsfor electrically connecting the atomizer, respectively the cartomizer,to a battery comprised in the battery portion when being attachedthereto. The elements and the counter-elements can be a pair of femaleand male coaxial threads, for instance.

In another exemplary embodiment depicted in FIG. 6, the spring isarranged between the plate 142 of the limiting element 140 and thethickened part 134 of the piston 130. The user, when pulling the piston130, increases the volume of the cavity with air entering through thepin hole 123 and compresses the spring 150. Once the user stops holdingthe piston 130, the spring moves the piston 130 back thereby reducingthe volume again and squirting out liquid trough the pin hole 123.

FIG. 7 is a schematic cross-sectional illustration of a furthercartomizer comprising a liquid reservoir according to an embodiment ofthe invention.

The cartomizer 100 comprises a hollow cylinder 110 having a plate 111with an axial hole 119 at one end. Through the axial hole 119 andfitting thereto passes a piston 130. The piston 130 has an annularlyprotruding ring 121 on one end 122. The ring's 121 outer diametercorresponds to the hollow cylinder's 110 inner diameter such that thehollow cylinder 110 can be closed at one end by insertion of the piston130 into the hollow cylinder 110 with a toroidal cavity remainingbetween the piston 130 and the cylinder 110. Around the ring there arean outer gasket ring, for instance in an annular furrow. At an innersurface of the axial hole 119 there is an outer gasket ring. The innergasket ring seals the piston 130 with respect to the plate. The outergasket ring seals the piston 130 with respect to the hollow cylinder110.

Alternatively, inner gasket ring is provided in the axial hole 119and/or the outer gasket ring is provided in the hollow cylinder. Thegasket rings may be positioned in an annular furrow.

Through the ring 121 there is a pin hole 123. Cylinder, ring, gasket andpin hole are configured such that once assembled the cavity is waterproof as long as pressure drop along the pin hole does not exceed athreshold pressure. I.e. to get liquid to escape from the cavity,through the pin hole, pressure has to be build up in the cavity.

For enabling a user to manually do so, the piston 130 can be moved inthe hollow cylinder 110.

Using the piston 130, the user then can change volume of the cavity andthus the pressure in the cavity.

A limiting element 140 is further comprised. The limiting element 140 ishollow and cylindrical and comprises a plate 142 at one end. An axialhole 143 is provided through the plate 142, the axial hole 143 having adiameter corresponding to an outer diameter of the piston 130. Thelimiting element 140 has an inner diameter corresponding to the outerdiameter of the hollow cylinder 110 such that the limiting element 140can be fit on the hollow cylinder 110. In the embodiment depicted thelimiting element 140 comprises a female thread and the hollow cylinder110 comprises a male thread such that the limiting element 140 and thehollow cylinder 110 can be screwed together. Exemplary other ways offitting comprise press-fit, snap-fit and the like.

In a middle section, the piston 130 comprises a thickened part 134, alsocalled annular protrusion throughout this specification, which has anouter diameter larger than the axial holes 119 and 143. Hence thethickened part 134 cannot pass through the axial holes. The limitingelement thereby limits, together with the plate of the hollow cylinder,movement of the piston 130.

Between the thickened part 134 of the piston 130 and the plate 142 ofthe limiting element 140 there is arranged a resilient element which inthe example illustrated is a spring 150. The piston 130 passes throughthe spring. The user, when pulling the piston 130 for reducing thevolume of the cavity, compresses the spring which, once the user stopsholding the piston 130, moves the piston 130 back. By pulling the piston130, volume of the cavity is reduced and pressure inside the remainingcavity is increased with liquid squirting through the pin hole once thepressure increase exceeds a threshold pressure. When the spring movesback the piston 130 air enters into the cavity through the pin hole.

FIG. 8 shows another exemplary embodiment of the invention, the springis arranged between the hollow cylinder and the thickened part 134 ofthe piston 130. The user, when pushing the piston 130, increases thevolume of the cavity with air entering through the pin hole 123 andcompresses the spring 150. Once the user stops holding the piston 130,the spring 150 moves the piston 130 back thereby reducing the volumeagain and squirting out liquid trough the pin hole 123.

The hollow cylinder 110 may be made of transparent material. Then theremaining liquid in the liquid reservoir 34 is well visible.

An aspect of the invention concerns a liquid reservoir 34 for anelectronic smoking device 10. The liquid reservoir 34 has a body 110forming a hollow tube surrounding a central passage 32 connecting an airinhalation port 36 with a further port for attaching the liquidreservoir 34 to a further portion of the electronic cigarette 10. Theliquid reservoir 34 further has a nozzle 132 towards the central passage32, the nozzle 32 being configured to release liquid from the reservoir34 only when pressure drop along the nozzle 32 exceeds a thresholdpressure. A user can produce the pressure drop by sucking at an airinhalation port 36 of the electronic smoking device 10 and/or bymanually changing a length of the central passage 32 thereby causingcompression of the liquid reservoir 34.

The pressure drop can be produced only by the user sucking at the airinhalation port 36. The pressure drop can be produced only bycompressing the liquid reservoir 34 such that a pressure in the liquidreservoir 34 is increased at least by the threshold pressure.

The liquid reservoir 34 may comprise a hollow cylindrical body 110closed on one end with a plate 121 in which the nozzle 123 is arrangedand having an open opposite end opposite to the one end. A piston 130may be inserted through the open end into the hollow cylindrical body110 for closing the open end. The user may be enabled to move the piston130 with respect to the hollow cylindrical body 110 for causingcompression of the liquid reservoir 34.

The cylindrical body 110 may form a toroidal cavity together with anaxial tubal element 120 extending along an axis of the cylindrical bodyand through the plate 121. The piston 130 may comprise a hollow rod 133at least partly surrounding the tubal element 120 wherein the hollow rod133 can be moved along the tubal element 120. The tubal element 120 andthe hollow rod 133 may surround the central passage 32, at least partly.

The piston 130 may further comprise at least one inner gasket 132sealing the hollow rod 133 with respect to the tubal element 120 and atleast one outer gasket 131 sealing the hollow rod 133 with respect tothe cylindrical body.

The user may be enabled to compress the liquid reservoir 34 from havinga first volume to having a smaller second volume.

A resilient element 150 may be present for expanding the compressedliquid reservoir 34 to the first volume once the user stops compressingthe liquid reservoir 34. The resilient element 150 may comprise a springarranged between the open end and an annular protrusion 134 around thehollow rod 133 of the piston 130. A limiting element 140 may be furthercomprised. The limiting element 140 may be configured to preventing thepiston 130 from exiting through the open end.

The user may be enabled to reduce a length of the central passage 12 forcompressing the liquid reservoir 34. Another aspect of the inventionconcerns a cartomizer. The cartomizer comprises a liquid reservoir 34and an electrically operable atomizer 26 configured for vaporizing oratomizing liquid supplied from the liquid reservoir 34 and for providingvaporized or atomized liquid as an aerosol. The liquid reservoir 34comprises a body 110 forming a hollow tube surrounding a central passage32 connecting ports for attaching the liquid reservoir 34 to furtherportions of the electronic cigarette 10. The liquid reservoir 34 has anozzle 123 towards the central passage 32. The nozzle 123 is configuredto release liquid from the liquid reservoir 34 only when pressure dropalong the nozzle 123 exceeds a threshold pressure. A length of thecentral passage 32 can be changed manually by a user thereby causingcompression of the liquid reservoir 34 such that a pressure in theliquid reservoir 34 is increased at least by the threshold pressure.

Yet another aspect of the invention concerns an atomizer/liquidreservoir portion 14 for an electronic smoking device 10. Theatomizer/liquid reservoir 14 portion comprises a liquid reservoir 34 andan electrically operable atomizer 26 configured for vaporizing oratomizing liquid supplied from the liquid reservoir 34 and for providingvaporized or atomized liquid as an aerosol. The liquid reservoir 34comprises a body 110 forming a hollow tube surrounding a central passage32 connecting ports. The liquid reservoir 34 has a nozzle 123 towardsthe central passage 32. The nozzle 123 is configured to release liquidfrom the liquid reservoir 34 only when pressure drop along the nozzle123 exceeds a threshold pressure. A length of the central passage 32 canbe changed manually by a user thereby causing compression of the liquidreservoir 34 such that a pressure in the liquid reservoir 34 isincreased at least by the threshold pressure.

Even yet another aspect of the invention concerns an electronic smokingdevice 10. The electronic smoking device 10 comprises one of: (a) acartomizer comprising a liquid reservoir 34, (b) an atomizer/liquidreservoir portion 14 comprising a liquid reservoir 34, and (c) a liquidreservoir 34 and an electrically operable atomizer 26 configured forvaporizing or atomizing liquid supplied from the liquid reservoir 34 andfor providing vaporized or atomized liquid as an aerosol where theatomizer 26 is operable when connected to a battery 18 of the electronicsmoking device 10 to atomize liquid stored in the liquid reservoir 34 asan aerosol. The liquid reservoir 34 comprises a body 110 forming ahollow tube surrounding a central passage 32 connecting ports 36, 38.The liquid reservoir 34 has a nozzle 123 towards the central passage 32.The nozzle 123 is configured to release liquid from the liquid reservoir34 only when pressure drop along the nozzle 123 exceeds a thresholdpressure. A length of the central passage 32 can be changed manually bya user thereby causing compression of the liquid reservoir 34 such thata pressure in the liquid reservoir 34 is increased at least by thethreshold pressure.

The electronic smoking device may further comprise a battery portion 12adapted for accommodation of one or more batteries 18 to which thecartomizer, the atomizer/liquid reservoir portion or the liquidreservoir may be releasably attached.

The

While this invention has been described in connection with what ispresently considered to be practical exemplary embodiments, it is to beunderstood that the invention is not limited to the embodimentsdisclosed, but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the scope ofthe appended claims.

LIST OF REFERENCE SIGNS 10 electronic smoking device 12 battery portion14 atomizer/liquid reservoir portion 16 end cap 18 battery 20 lightemitting diode (LED) 22 control electronics 24 airflow sensor 26atomizer 28 heating coil 30 wick 32 central passage 34 liquid reservoir36 air inhalation port 38 air inlets 100 cartomizer 110 hollow cylinder111 plate 119 axial hole 120 tubal element 121 ring protrusion 123nozzle, pin hole 130 piston 131 outer gasket ring 132 inner gasket ring133 hollow rod 134 thickened part, annular protrusion 140 limitingelement 142 plate 143 axial hole 150 resilient element, spring

1. A liquid reservoir for an electronic smoking device, the liquidreservoir comprising: a body forming a hollow tube surrounding a centralpassage; connecting ports for attaching the liquid reservoir to furtherportions of the electronic cigarette; and a nozzle towards the centralpassage, the nozzle being configured to release liquid from the liquidreservoir only when pressure drop along the nozzle exceeds a thresholdpressure wherein the pressure drop can be produced by a user sucking atan air inhalation port of the electronic smoking device and/or manuallychanging a length of the central passage thereby causing compression ofthe liquid reservoir.
 2. The liquid reservoir of claim 1 wherein thepressure drop can be produced only by the user sucking at the inhalationport.
 3. The liquid reservoir of claim 1 wherein the liquid reservoircomprises a hollow cylindrical body closed on one end with a plate inwhich the nozzle is arranged and having an open end arranged opposite tothe one end wherein the piston is inserted through the open end into thehollow cylindrical body for closing the open end and wherein the usercan move the piston with respect to the hollow cylindrical body forcausing compression of the liquid reservoir.
 4. The liquid reservoir ofclaim 3 wherein the cylindrical body forms a toroidal cavity togetherwith an axial tubal element extending along an axis of the cylindricalbody and through the plate, and wherein the piston comprises a hollowrod at least partly surrounding the tubal element wherein the hollow rodcan be moved along the tubal element.
 5. The liquid reservoir of claim 4wherein the tubal element and the hollow rod at least partly surroundthe central passage.
 6. The liquid reservoir of claim 4 wherein thepiston further comprises at least one inner gasket ring sealing thehollow rod with respect to the tubal element and at least one outergasket ring sealing the hollow rod with respect to the cylindrical body.7. The liquid reservoir of claim 1 wherein the user can compress theliquid reservoir from having a first volume to having a smaller secondvolume.
 8. The liquid reservoir of claim 7 further comprising aresilient element for expanding the compressed liquid reservoir to thefirst volume once the user stops compressing the liquid reservoir. 9.The liquid reservoir of claim 8 wherein the resilient element comprisesa spring arranged between the open end and an annular protrusion aroundthe hollow rod of the piston.
 10. The liquid reservoir of claim 9further comprising a limiting element configured to prevent the pistonfrom exiting through the open end.
 11. The liquid reservoir of claim 1wherein the length of the central passage is reducible by the user forcompressing the liquid reservoir.
 12. A Cartomizer for an electronicsmoking device, the cartomizer comprising the liquid reservoir of claim1, wherein the cartomizer further includes an electrically operableatomizer configured for vaporizing or atomizing liquid supplied from theliquid reservoir and for providing vaporized or atomized liquid as anaerosol.
 13. An atomizer/liquid reservoir portion for an electronicsmoking device, the atomizer/liquid reservoir portion comprising theliquid reservoir of claim 1, wherein the atomizer/liquid reservoirportion further includes an electrically operable atomizer configuredfor vaporizing or atomizing liquid supplied from the liquid reservoirand for providing vaporized or atomized liquid as an aerosol.
 14. Anelectronic smoking device comprising: the liquid reservoir of claim 1;and a battery portion comprising the battery.
 15. The electronic smokingdevice of claim 14 wherein the liquid reservoir is included in acartomizer for the electronic smoking device, and wherein the cartomizerfurther includes an electrically operable atomizer configured forvaporizing or atomizing liquid supplied from the liquid reservoir andfor providing vaporized or atomized liquid as an aerosol.
 16. Theelectronic smoking device of claim 14 wherein the liquid reservoir isincluded in an atomizer/liquid reservoir portion for an electronicsmoking device, and wherein the atomizer/liquid reservoir portionfurther includes an electrically operable atomizer configured forvaporizing or atomizing liquid supplied from the liquid reservoir andfor providing vaporized or atomized liquid as an aerosol.
 17. Theelectronic smoking device of claim 14 further comprising an electricallyoperable atomizer configured for vaporizing or atomizing liquid suppliedfrom the liquid reservoir and for providing vaporized or atomized liquidas an aerosol where the atomizer is operable when connected to a batteryof the electronic smoking device to atomize liquid stored in the liquidreservoir as an aerosol.